This section provides background information related to the present disclosure which is not necessarily prior art.
A hung window assembly comprises a window sash that moves within a window frame. The window frame guides the window sash as it moves between an OPENED and CLOSED position (i.e., an up and down movement of the sash). In order to counter the weight of the window sash, and provide for smooth operation of the window assembly to a user both in an upward and in a downward manner, a balance assembly is incorporated in the hung window assembly. Generally, the balance assembly is mounted to the frame of the window system, such as within the jamb channel. The window sash engages a carrier which is connected to the balance assembly. Accordingly, the balance assembly is interconnected with the window sash through the carrier.
Balance assemblies that counter the weight of the window sash can take the form of various generally known mechanisms, including a block-and-tackle balance assembly, a spiral balance assembly, and a hybrid balance assembly. In a block-and-tackle assembly a pulley system can operate with a spring to overcome the force of gravity on the window sash. In a spiral or hybrid balance assembly, a torsion spring can be employed to assist in overcoming the force of gravity on the window sash.
These known balance assemblies, however, can also generate other forces and/or force components in addition to those that counter the weight of the window sash. These forces and/or force components can include lever forces, moments, and/or torques that tend to urge or bind the carrier against the jamb channel thereby creating friction forces between the carrier and the jamb channel during movement of the window sash. To operate the window sash, then, these additional frictional forces must also be overcome by the user. As a result, the consistent and smooth operation of the window assembly can be compromised.